121 - 4 - A

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121 - 4 - A
2013-04-25 05:45:02

Review of Signaling System Organization
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  1. All signaling systems do what?
    Allow communication between two cells
  2. What are the basic molecular components of signaling systems?

    Target Cell

    Signal Transduction Pathway

    Effector Mechanism
  3. Where do ligands come from?
    Signaling Cell (cell they originated from)
  4. What are ligands also known as?
    Primary Signal molecule
  5. Target Cells are known as?
    Primary Responding Molecule
  6. A primary responding molecule (target cell) that is on a cell that is receiving communication is called?
    A receptor
  7. Signal transduction pathway is also known as?
    The second messenger cascade
  8. In a receiving cell, the intracellular series of signal transducing molecules are called?
    Signal transduction pathway (second messager cascade)
  9. Effector mechanism is also known as?
    Target mechanism
  10. In receiving cell, the molecular event that the signal is meant to produce is called?
    Effector mechanism (Target mechanism)
  11. In an aqueous organism, what are the two ways ligand can access their receptor on the downstream cell?
    • (1) Ligands secrete into the fluids of the body
    • (2) ligands can transduce (transfer) information through cellular contact
  12. What are the three aqueous environments that cells can secrete ligands?
    Blood -- Endocrine Ligands

    Local Fluids -- Paracrine Ligands

    Neuronal Synapse -- neurotransmitter
  13. Ligands dispersed into the blood...
    can reach all cell type in the body
  14. Ligands dispersed into the local fluids...
    reach a selected few cell types within a tissue
  15. Ligands dispersed into a neuronal synapse...
    can reach as few as a single cell
  16. Signaling through cellular contact can use either?
    Soluble Ligands ( in the form of second messenger molecules)


    Immobilized Ligand
  17. Signal Transduction Pathway is?
    Are used by cells to convert chemical messages to cellular action
  18. Closely related cells can communicate... how?
    Without secretion of ligands into the extracellular space, they are able to communicate by directly sharing second messenger molecules in their cytosol through gap junctions
  19. Immobilized ligands on the surface of cells or in the extracellular matrix of tissues can what?
    bind to downstream cell receptors and function just like soluble ligands
  20. All cells build their ability to respond to specific signals into their phenotype by

    second messenger cascades (signal transduction (transfer) pathway)

    target/effector mechanisms

    that they express
  21. The cellular response to a single or multiple signals is...
    hard-wired and can only change if there is a change in phenotype.
  22. What are the two major classes of receptor proteins in the cells of multicellular organisms?
    (1) The ones that are in the transmembrane in the plasma membrane will respond to water soluble ligands

    (2) The ones inside of the cell will respond to ligands that are able pass the plasma membrane
  23. Why are intracellular second messenger cascades are complex?
    in order for the cell to control them better and allowing multiple signaling pathways to communicate inside the cell
  24. One or more target mechanism are what?
    hard-wired to every signal cascade and can only be changed if phenotype changed